2022-04-19 14:56:28

by Maciej W. Rozycki

[permalink] [raw]
Subject: [PATCH v5 0/5] serial: 8250: Fixes for Oxford Semiconductor 950 UARTs

Hi,

Here's v5 of the outstanding fixes for Oxford Semiconductor 950 UARTs
including most updates requested by Andy (thanks for your review!).

Also while looking into an unrelated issue I have come across the
DIV_ROUND_CLOSEST macro and updated 5/5 replacing equivalent handcoded
calculations. I have verified that there is no change in machine code
produced after this update with the i386 and RISC-V targets.

Please apply.

Maciej


2022-04-19 16:47:17

by Maciej W. Rozycki

[permalink] [raw]
Subject: [PATCH v5 1/5] serial: 8250: Also set sticky MCR bits in console restoration

Sticky MCR bits are lost in console restoration if console suspending
has been disabled. This currently affects the AFE bit, which works in
combination with RTS which we set, so we want to make sure the UART
retains control of its FIFO where previously requested. Also specific
drivers may need other bits in the future.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend")
Cc: [email protected] # v4.0+
Reviewed-by: Andy Shevchenko <[email protected]>
---
Changes from v4:

- Reorder as 1/5 (from 4/5).

New change in v4, factored out from 5/5.
---
drivers/tty/serial/8250/8250_port.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

linux-serial-8250-mcr-restore.diff
Index: linux-macro/drivers/tty/serial/8250/8250_port.c
===================================================================
--- linux-macro.orig/drivers/tty/serial/8250/8250_port.c
+++ linux-macro/drivers/tty/serial/8250/8250_port.c
@@ -3308,7 +3308,7 @@ static void serial8250_console_restore(s

serial8250_set_divisor(port, baud, quot, frac);
serial_port_out(port, UART_LCR, up->lcr);
- serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);
+ serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS);
}

/*

2022-04-19 18:18:54

by Maciej W. Rozycki

[permalink] [raw]
Subject: [PATCH v5 3/5] serial: 8250: Fold EndRun device support into OxSemi Tornado code

The EndRun PTP/1588 dual serial port device is based on the Oxford
Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set
for EndRun Technologies and uses the same sequence to determine the
number of ports available. Despite that we have duplicate code
specific to the EndRun device.

Remove redundant code then and factor out OxSemi Tornado device
detection.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
Changes from v4:

- Reorder as 3/5 (from 2/5).

Changes from v3:

- Factor out baud base correction along with the `Fixes' tag to 1/5.

- Discard the change to move the EndRun vendor:device ID macros to
<linux/pci_ids.h>.

New change in v3.
---
drivers/tty/serial/8250/8250_pci.c | 76 ++++++++++++-------------------------
1 file changed, 25 insertions(+), 51 deletions(-)

linux-serial-8250-oxsemi-endrun.diff
Index: linux-macro/drivers/tty/serial/8250/8250_pci.c
===================================================================
--- linux-macro.orig/drivers/tty/serial/8250/8250_pci.c
+++ linux-macro/drivers/tty/serial/8250/8250_pci.c
@@ -994,41 +994,29 @@ static void pci_ite887x_exit(struct pci_
}

/*
- * EndRun Technologies.
- * Determine the number of ports available on the device.
+ * Oxford Semiconductor Inc.
+ * Check if an OxSemi device is part of the Tornado range of devices.
*/
#define PCI_VENDOR_ID_ENDRUN 0x7401
#define PCI_DEVICE_ID_ENDRUN_1588 0xe100

-static int pci_endrun_init(struct pci_dev *dev)
+static bool pci_oxsemi_tornado_p(struct pci_dev *dev)
{
- u8 __iomem *p;
- unsigned long deviceID;
- unsigned int number_uarts = 0;
+ /* OxSemi Tornado devices are all 0xCxxx */
+ if (dev->vendor == PCI_VENDOR_ID_OXSEMI &&
+ (dev->device & 0xf000) != 0xc000)
+ return false;

- /* EndRun device is all 0xexxx */
+ /* EndRun devices are all 0xExxx */
if (dev->vendor == PCI_VENDOR_ID_ENDRUN &&
- (dev->device & 0xf000) != 0xe000)
- return 0;
-
- p = pci_iomap(dev, 0, 5);
- if (p == NULL)
- return -ENOMEM;
+ (dev->device & 0xf000) != 0xe000)
+ return false;

- deviceID = ioread32(p);
- /* EndRun device */
- if (deviceID == 0x07000200) {
- number_uarts = ioread8(p + 4);
- pci_dbg(dev, "%d ports detected on EndRun PCI Express device\n", number_uarts);
- }
- pci_iounmap(dev, p);
- return number_uarts;
+ return true;
}

/*
- * Oxford Semiconductor Inc.
- * Check that device is part of the Tornado range of devices, then determine
- * the number of ports available on the device.
+ * Determine the number of ports available on a Tornado device.
*/
static int pci_oxsemi_tornado_init(struct pci_dev *dev)
{
@@ -1036,9 +1024,7 @@ static int pci_oxsemi_tornado_init(struc
unsigned long deviceID;
unsigned int number_uarts = 0;

- /* OxSemi Tornado devices are all 0xCxxx */
- if (dev->vendor == PCI_VENDOR_ID_OXSEMI &&
- (dev->device & 0xF000) != 0xC000)
+ if (!pci_oxsemi_tornado_p(dev))
return 0;

p = pci_iomap(dev, 0, 5);
@@ -1049,7 +1035,10 @@ static int pci_oxsemi_tornado_init(struc
/* Tornado device */
if (deviceID == 0x07000200) {
number_uarts = ioread8(p + 4);
- pci_dbg(dev, "%d ports detected on Oxford PCI Express device\n", number_uarts);
+ pci_dbg(dev, "%d ports detected on %s PCI Express device\n",
+ number_uarts,
+ dev->vendor == PCI_VENDOR_ID_ENDRUN ?
+ "EndRun" : "Oxford");
}
pci_iounmap(dev, p);
return number_uarts;
@@ -2244,7 +2233,7 @@ static struct pci_serial_quirk pci_seria
.device = PCI_ANY_ID,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .init = pci_endrun_init,
+ .init = pci_oxsemi_tornado_init,
.setup = pci_default_setup,
},
/*
@@ -2667,7 +2656,6 @@ enum pci_board_num_t {
pbn_panacom2,
pbn_panacom4,
pbn_plx_romulus,
- pbn_endrun_2_3906250,
pbn_oxsemi,
pbn_oxsemi_1_3906250,
pbn_oxsemi_2_3906250,
@@ -3190,20 +3178,6 @@ static struct pciserial_board pci_boards
},

/*
- * EndRun Technologies
- * Uses the size of PCI Base region 0 to
- * signal now many ports are available
- * 2 port 952 Uart support
- */
- [pbn_endrun_2_3906250] = {
- .flags = FL_BASE0,
- .num_ports = 2,
- .base_baud = 3906250,
- .uart_offset = 0x200,
- .first_offset = 0x1000,
- },
-
- /*
* This board uses the size of PCI Base region 0 to
* signal now many ports are available
*/
@@ -4123,13 +4097,6 @@ static const struct pci_device_id serial
0x10b5, 0x106a, 0, 0,
pbn_plx_romulus },
/*
- * EndRun Technologies. PCI express device range.
- * EndRun PTP/1588 has 2 Native UARTs.
- */
- { PCI_VENDOR_ID_ENDRUN, PCI_DEVICE_ID_ENDRUN_1588,
- PCI_ANY_ID, PCI_ANY_ID, 0, 0,
- pbn_endrun_2_3906250 },
- /*
* Quatech cards. These actually have configurable clocks but for
* now we just use the default.
*
@@ -4390,6 +4357,13 @@ static const struct pci_device_id serial
{ PCI_VENDOR_ID_DIGI, PCIE_DEVICE_ID_NEO_2_OX_IBM,
PCI_SUBVENDOR_ID_IBM, PCI_ANY_ID, 0, 0,
pbn_oxsemi_2_3906250 },
+ /*
+ * EndRun Technologies. PCI express device range.
+ * EndRun PTP/1588 has 2 Native UARTs utilizing OxSemi 952.
+ */
+ { PCI_VENDOR_ID_ENDRUN, PCI_DEVICE_ID_ENDRUN_1588,
+ PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+ pbn_oxsemi_2_3906250 },

/*
* SBS Technologies, Inc. P-Octal and PMC-OCTPRO cards,